Silicon carbide single crystal substrate

6. The silicon carbide single crystal substrate according to claim 5, wherein when the detector is positioned in the direction parallel to the [−1100] direction when viewed in the direction perpendicular to the main surface and a location to be irradiated with the X ray is changed in a range of ±6° relative to the [1-100] direction, an absolute value of a difference between maximum value and minimum value of energy at which the second intensity profile indicates a maximum value in the range of 8.0 keV to 9.5 keV is less than or equal to 0.08 keV.